This looks incredibly cool; I'm going to grab it and try it out!
By the way, what would the implications be of making the type "Asteroid" versus "Low Tech"? Does that affect anything?
Also, (if this isn't present already) I think it would be fun to have a built-in "Heavy Mass Driver" weapon like in Knights of Sidonia (which, incidentally, stars an asteroid ship) or Star Control 2's Druuge Mauler. It would essentially shoot a high-velocity (well, low compared to most projectiles) small asteroid taken from its own body, with no distance limit. Once launched this would just be like any other asteroid at that speed, for purposes of collisions, damage, momentum, etc.
Edit:
So on initial inspection, I've noticed:
1) Boulder (shuttle) is too small (size of a fighter); ships drilled out of rocks should be larger than equivalent ships made of actual metals. Also it's WAY too cheap to deploy; it gets 2% CR to deploy and 6% recovery per day, yet has the loadout of a Kite. Yet the maintenance is unreasonably high (3) for basically a low-tech drilled-out rock. Also it has 180 degree shields with 15 flux upkeep, which seems absurd for a low-tech DIY pirate ship. E.g. Mudskipper has no shield, while Shepherd has a 90 degree 1.2 shield, and they both have 20% deployment CR.
2) Cerus (cruiser) has extremely high stats with 16 small and 3 medium slots, plus a fighter bay. And 300 degree 0.8 shields with 8000 base flux capacity, 600 base dissipation, and 75 speed... on a gigantic rock. Oh, and weak (400) armor? I would expect DIY asteroid ships cobbled (heh) together by pirates to be very slow, with very heavy armor, weak or no shields, and insufficient flux, not... midline-grade shields, best-in-class powerplants, and near-best-in-class speed. And all that for 15 deployment points? Consider the specs of a (also 15 DP) Falcon (P); it could probably crush 3 Falcons. At once.
Those are the only ships I've seen so far but while the art is fantastic, I think the balance could use a bit of tweaking.